1. Field of the Invention
The present invention relates to a photosensitive composition capable of changing the property by reaction upon irradiation with actinic ray or radiation (X-ray, electron beam, EUV, etc.), a compound for use in the photosensitive composition, and a pattern-forming method using the photosensitive composition. More specifically, the invention relates to a photosensitive composition for use in a manufacturing process of semiconductors, e.g., IC, the manufacture of circuit substrates for liquid crystals, thermal heads and the like, other photo-fabrication processes, lithographic printing plates, and acid-curable compositions, and also the invention relates to a compound for use in the photosensitive composition, and a pattern-forming method using the photosensitive composition.
2. Description of the Related Art
Chemical amplification resist compositions are pattern-forming materials capable of generating an acid at the area irradiated with radiation such as a far ultraviolet ray, changing the solubility in a developer of the area irradiated with the actinic radiation and the non-irradiated area by the reaction with the acid as a catalyst, and forming a pattern on a substrate.
When a KrF excimer laser is used as the exposure light source, since resins having poly(hydroxystyrene) that is small in absorption in the region of 248 nm as a fundamental skeleton are mainly used, the compositions are high sensitivity, high resolution and good patterns can be formed as compared with conventionally used naphthoquinonediazide/novolak resins.
On the other hand, when a light source of further shorter wavelength, e.g., an ArF excimer laser (193 nm), is used as the exposure light source, since compounds containing an aromatic group substantially show large absorption in the region of 193 nm, even the chemical amplification resist compositions are not sufficient.
To cope with this problem, resists for an ArF excimer laser containing a resin having an alicyclic hydrocarbon structure have been developed.
Regarding an acid generator that is the main constituent of chemical amplification resists, triphenylsulfonium salts are generally known (e.g., refer to U.S. Pat. No. 6,548,221).
However, these acid generators are still insufficient in various points, so that photosensitive compositions that are improved in sensitivity, resolution, a pattern form, and roughness are desired.
Further, when light sources such as electron beams, X-rays and EUV are used, exposure is carried out under vacuum, so that compounds having a low boiling point such as solvents and resist materials decomposed by high energy are volatilized to thereby contaminate the exposure apparatus, i.e., outgassing is a serious problem. In recent years, various investigations are in progress on the reduction of outgassing, and a variety of trials are suggested, e.g., restraint of volatilization of low molecular weight compounds by forming a top coat layer (e.g., refer to EP 1480078), and addition of a radical trapping agent capable of inhibiting decomposition of a polymer (e.g., refer to U.S. Pat. No. 6,680,157). Some contrivances of outgassing are also required in connection with acid generators.